It would be awesome to have such a variety of coins in use, but these coins are not meant to ever be spent. Mints have the technology and expertise to make coin-like objects, so many branch out and use this power to create collectible coins (also known as collector coins) - special, limited-run coins that usually both commemorate some important person, place, thing, or event, and which frequently make use of technology, design, or materials that would be too expensive in an every-day coin. In recent years, it's not uncommon to also find tie-ins to movies (The Hobbit, Transformers) or well-known characters (Scooby-Doo, Dr. Who).
|Canada's 2012 Prehistoric Animals dinosaur|
collectible coin with glow-in-the-dark skeleton
Collectible coins have a denomination (value) on them so that they can be considered a coin instead of a medal or token. This technically makes them legal tender (able to be spent), but the cost of acquiring the coin makes it impractical to actually spend. For example, the Pachyrhinosaurus coin pictured above has a denomination of 25 cents (Canadian), but it will cost $30 to get one - 120 times the value printed on the coin itself.
In contrast, circulating coins are the coins that you use on a daily basis - you get them as change, you find them on the ground, or you spend them in vending machines. These coins are made of inexpensive metal, the design doesn't change very often, and the mints produce thousands if not millions of them each year. You usually don't buy these coins directly from the mint - banks trade in old, worn-out coins for new coins from the mint so that the number of coins in use stays around the same. To get a circulating coin, you either get it as change from a sales transaction, or you can go directly to a bank and "buy" one by trading in an equal amount of money (for example, trading 1 dollar for 4 25-cent coins). (One exception to this are mints, like the US Mint, that sell bags or rolls of uncirculated coins.)
Because of their higher cost, you need to protect collectible coins differently than you would protect regular circulating coins. A folded paper flip isn't going to be enough. Many collectible coins sold today come in their own protective hard-plastic container. This protects them from dust, scratches, water, fingerprints, and other wear (and should never be opened). If you get a collectible coin that doesn't have such a container, visit your local coin shop and get something that will fit the coin securely and tightly - you don't want it to slide around in its protective case.
As a world coin collector, you can specialize in either collectible coins, circulating coins, or of course both. Because collectible coins are so much more expensive, it is more common to start out collecting circulating coins (especially for kids). However, collectible coins make great gifts, especially if you find one with a subject that the recipient will find interesting.